Behavioral characteristics of thread-sail filefish (Stephanolepis cirrhifer) measured by acoustic telemetry

Abstract

Understanding movement patterns and habitat of the target species is important in the application of an ecosystem approach to fisheries management. The swimming paths of two thread-sail filefish (Stephanolepis cirrhifer) were measured in Tongyeong to appreciate how to use the space inside the experimental cage and in the open sea. The fish were surgically tagged with the acoustic transmitters (including a depth sensor). Passive monitoring and active tracking methods were carried out for 4 days and 3 hours, respectively. Horizontal movements in the cage were affected by current direction. During high current speed (>15 cm/s), fish were more active and cumulated horizontal distances almost double of those at low current. Vertical movements of fish were affected by high current speed that reduced the depth of the cage bottom. When the current exceed 15 cm/s, the depth of the cage bottom was reduced. Furthermore fish were closer to the cage bottom at those moments. After release the fish were tracked for 41 minutes and moved 150 m from the release point.